Automatic interchangeable circuit interrupter or circuit breaker



W. S. MAYER May 11, 1937.

AUTOMATIC INTERCHANGEABLE CIRCUIT INTERRUPTER OR CIRCUIT BREAKER 2Sheets-Sheet 1 Filed. Sept. 24, 1934 45b 4.4a, V i .5

H6 XI N V EN TOR A TTORNEYS.

May 11, 1937. w 5 MAYER 2,079,866

AUTOMATIC INTERCHANGEABLE CIRCUIT INTERRUPTER OR CIRCUIT BREAKER FiledSept. 24, 1934 2 Sheets-Sheet 2 Jig/Wam- W INVENTOR.

A TTORNEYS.

Patented May 11, 1937 UNITED STATES AUTOMATIC INTERCHANGEABLE CIRCUITINTERRUPTER OR CIRCUIT BREAKER Walter s. Mayer, Philadelphia, Pa.Application September 24, 1934, Serial No. 745,232

9 Claims,

A principal object of my invention is to provide a device readilyinsertable in electric circuits for repeatedly automatically breakingthe circuit upon the occurrence of overloads or short circuits, withoutinjury to the device, that has few parts, is inexpensive to manufacture,and which device must be removed from the circuit in order to haveaccess to manually reset the interrupting means, and which does notpermit 10 manually interfering with, or holding of, the interruptingmeans when the device is inserted in the electric circuit.

Other objects of my invention are,--to provide a circuit,interrupterwhich is fully enclosed by an insulated casing so that the live parts ofthe mechanism can not be manually touched,that has an automatic delayedtime action,-that has electrodes or terminals of the ferrule or knifeblade type, or equivalent, rigidly connected to an insulated casingprotecting said terminals from manual contact,-'-which may be insertedin standard National Electric Code fuse clips or the like, similar tothe commercial fuse,--and .that has combinations of construction whichpermit the device being made in such sizes that its lengths correspondto the lengths of the N. E. Code fuses, hence thereby beinginterchangeable with the commercial N. E. Code fuses.

My invention also, consists of certain novel features of construction aswill be fully described and pointed out in the detailed description, thedrawings, and the appended claims.

Referring to th drawings: Fig. I shows a plan view of my circuit breakerwith the cover component of the casing removed. Fig. II is a sectionalview taken along the line II--II of Fig. I showing closed position ofthe circuit breaker.

. Fig. III is a plan view of my breaker with the cover component inplace.

Fig. IV is a side elevation of Fig. I but with the cover component inplace.

Fig. V is a section taken as in Fig. II except that it shows the openposition of the breaker.

Fig. VI is a bottom view of Fig. II. N

Fig. VII is a section taken as in Fig. II but with the cover componentremoved and with a modifled latching mechanism.

Fig. VIII is a part section taken as in Fig. VII

60 but with another modified latching mechanism.

Fig. IX is a perspective view of the pivoted switching arm, or movablecontact structure.

Fig. X is a perspective view of the contact with its insulated blow outmagnet secured thereto.

60 Fig. XI is a perspective view of the thermal tripping element, shownin Fig. II, and Fig. III.

Fig. XII is a fragmentary sectional view showing an overload deviceconnected to the circuit controller. L

With more specific reference to the drawings, 5 my automaticinterchangeable circuit breaker comprises a box like casing l4, which ispreferably of moulded insulation, and which encloses the working partslater on individually referred to. As shown the casing l4, consists of acover com- 10 ponent l5, and a base component I6, which meet in arabbetted juncture l1 whereby the two are held in perfect alignment andregistry. The cover component I5, is removably secured to the basecomponent l6, by screws l8 which pass thru 16 counterbored openings inits side walls into internally threaded bushings l9 embedded in the basecomponent. See Fig. I and Fig. IV. These counterbores may be filled withcompound if it is desired to seal the cover in place. 20

Lodged within external recesses 20, 2|, of the base component It, aremetallic tubular terminals 22, 23 capable of engagement with springclips, such as standard N. E. Code fuse clips. Referring to Fig. IV, astandard 60 ampere fuse 5 clip 23a, is shown secured to the panel orswitchboard 33b, andthe tubular terminal 23; is shown engaging the fuseclip 23a. It is quite obvious that knife blade terminals could besubstituted, with slight modifications, in place of the tubular 3terminals.

With provisions above described, my breaker may be readily substitutedin place of an ordinary cartridge fuse.

To facilitate application and removal from the 35 spring clips, Ihave'provided grasp projections 24 on the cover component IS. The graspprojections form a seat for a name plate 25 which is .secured thereto byescutcheon pins 25a.

The cover component is ,provided withopen- 40 ings l5a, through whichthe position of the switching arm, or movable contact structure, isvisible, so that in looking at the device on a plan, view, its conditionas to On or Off is readily visible. 45

The words On and Off are marked on the cover as shown. The openings l5a,also serve as are vents.

As a further visual indication of the switching arm, and its position inthe casing, the cover component l5 may be made of moulded glass.

The tubular terminal 23, and a V shaped metal contact 26, areelectrically connected together and rigidly secured to the basecomponent, by means of the metallic screw 21. The tubular 'idiy securedto the base comw 38 with a washer 23 interl internai recess of the baseswitching arm, or is located. This switching arm is erspective at Fig.IX as heretofore en.

The swltchii mm, or movable contact struc ture, consists or sheet metaopen trough shaped member, having two legs 3;, 32, and a flat cross yokeconnectin the legs, which yoke is an integrai of the member and isdesignated as 33. The eggs 33, are also connected together by thecylindrical hub 34, through which the bearing pin 34a is positioned, andon which the switching arm as a whole, pivots.

The cylindrical hub, 34, has a longitudinal groove 34b, and one edge ofwhich as 340, acting as a stop or catch, engages with a lip 45a of thethermal element 45 to hold the switching arm in the closed position,thus forming a restraining means, and the other edge of which as 34dforms a seat for the looped end 46a of the spring 46. The spring 46,envelops the bearing pin 34a on the outside of the legs 3|, 32 of theswitching arm as clearly shown in the several figures. The outer ends ofthe bearing pin 340. are secured in the base component Hi. In additionto the functions aforestated, the cylindrical hub 34 is slotted as at34c, so that a screw driver or detachable handle, or equivalent may beinserted to rotate the switching arm as a whole from the off position tothe closed position when the device as a whole is removed from thespring clips.

A slot or aperture ISb, in the base component 13, permits a screw driveror equivalent to be inserted into the slot 346 of the switching arm forresetting, but the cylindrical portion of the hub 34, adjacent the slot15b, practically closes the slot 16b to any attempt to push the screwdriver etc., beyond or around the hub and into the body of the basecomponent or into the enclosed mechanism, and said slots are onlyaccessible when the device as a whole is removed from the spring clips,and therefore electric circuit.

The end 452) of the thermal element 45, is rigidly riveted to the fioorportion 22b of the tubular terminal 22, as clearly shown in Fig. II, andthus makes perfect electrical contact therewith. The thermal element45,passes thru an opening 56 in the base 16, which however is screened bythe tubular terminal 22. By passing the thermal element thru saidopening and into the cylinder portion of terminal 22, I obtain increasedlength and therefore greater flexibility of the thermal element.

With further reference to the switching arm, a leaf metallic spring 35,U shape in form, is secured to the yoke 33 by a tubular rivet 36, thefree end of said spring has a non-arcing conducting block 38 rivetedthereto by means of the solid shouldered rivet 39. This rivet passesthru the tubular rivet 36, and the shouldered head of the rivet 39limits the movement of the conducting block 38 in the direction of thecontact 26, as the switching arm moves to off position.

In the closed position shown in Fig. II, it will be noted that theconducting block 38, under action of the spring 35, makes a fiatpressure contact of high electrical conductivity, with the V shapedstationary contact 26. Hence there is no possibility of the surfacessticking as would be the case if a knife blade contact arrangement wereemployed.

aovasee The tubular rivet 36, also secures to the yoke 33, the connector4!, which has coiled portions 42, 42, into which the flexible strandedcopper shunt wires 43, 43, are secured. It will be noted that the shunt43, is looped from the connector M to the connector 450. The loop is tocompensate for the movement of the switching arm, and the iunctio' theshunt as a whole, is to conduct the curre n from the thermal element theswitching Thus the path or the current thru the device, is from thetubular terminal 22, thru the thermal element 45, thru the shunt 43,thru the leaf spring 35, to the contact block 38, thru the contact 26,thru the screw 21, to the tubular terminal 23, or in the reversedirection.

The spring 46 tends to move the switching arm to the open position fromthe closed position, and the spring initially assists, but the tendencyis restrained from so doing by reason of the lip a of the thermalelement, engaging the stop 340 of the switching a-rm hub 34. Howeverwhen an overload or short circuit, or other abnormal circuit conditionoccurs, the thermal element deflects, with delayed time action, so thatthe lip 45a is raised or disengaged from the stop 34c, and thus theswitching arm is rapidly moved to the oil position by reason of theaction of the aforesaid springs. See Fig. V.

If it is desired to have instantaneous action on a short circuit, anddelayed action on an ordinary overload, my device lends itself toincorporating an electromagnet in combination with the thermal elementto accomplish the purpose. wherein an electrical bridging member ispivoted at 64. A standard 63 provides one bearing about which trip arm6| oscillates. The trip arm 3| has a notch or hook therein whichreceives a cooperative roller, the latter being securely mounted on theoscillatory bridging member, and when the free end of the trip arm israised, the hook is disengaged from the roller. It is to be noted that athermal element in normal position does not interfere with the trip 6|but upon carrying an overload the heating of the element causes it tomove upwardly thereby tripping the trip GI and releasing the bridgingmember. An armature 62 of an electromagnet and armature unit is securelyattached to the trip SI and upon an overload occurring, the trip GI israised to release the oscillatory bridging member. The armature 52 maybe considered as the instantaneous breaker and the thermal element asthe time delay breaker.

As shown in Fig. VI-the words On and 011 are also imprinted on the basecomponent IE to indicate by the position of the screw driver slot 346,or equivalent, as to whether the device is closed or open.

In the modified mechanism shown in Fig. VIII a considerable reduction inthe friction to tripping is effected by using a roller 48 with a bearingpin 48a associated therewith on the switching arm, instead of the edge340 of the hub 34 shown in Fig. IX. The end of the thermal element 4!!as shown in Fig. VIII is modified to engage the roller 48, and alsoprovided with a stop 49a to prevent overtravel.

In the other modified latching mechanism Fig. VII, 9. further reductionin the tripping efl'ort is effected, and furthermore the thermal element50, is relieved of compression strain. As shown the base component I6 ismodified to have bearlng lugs 30a located in the recess 30. A pivot InFig. XII I show a circuit controller pin 30b passing thru the lugs, hasiulcrumed on it a trigger 300 which engages the roller 30d on itscoordinating bearing pin 30c attached to the switching arm. A spring 30fcontrols the trigger pressure and alignment. The thermal element 50 issecured to the cylindrical wall of the tubu iar terminal 22 in Fig. VIIat one end, and is looped or spiral in form so as to give increasedlength and hence greater deflection. As the thermal element 50 deflectsdue to overload or short circuit, the free end raises the trigger 300 todisengage the roller and allows the switching arm to fly or rapidly moveto the open position. It will be noted that the point of pressure of thethermal element on the trigger 300 is over twice the distance from thepivot pin 30b, as is the holding force applied at the roller 30d. Hencethe tripping pressure of the thermal element to release the switchingarm in Fig. VII is only half as great as that required by the thermalelement of the modification shown in Fig. VIII.

The U shaped blow out magnet 26b envelope one leg of the V shapedcontact 26 and has a U shaped insulating shield 26a interposed so thatany are, between 38 and 26 will not flash on the sides of the magnet26b. The object of the blow out is to facilitate the extinguishing andruptur ing of the arc, incident upon 38 moving out of circuit with 26. r

Further-in connection with the modification shown in Fig. VII, it willbe noted that in place of a' screw driver slot in the hub of theswitching arm for moving said arm to closed position, I have substituteda finger piece i so that the device-may be closed with the finger orequivalent. I

The side barriers Ila and 22a of the recesses 2i and 20 prevent thedevice from being inserted sidewise into the spring clips, which wouldex- .pose the slot or aperture l6b of the base component i6, andincidently the manual operating end of the switching arm as the slot346. The aforesaid barriers, also partly cover and thus prevent manualcontact with the -fuse or spring clips as 23a. See Fig. IV.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. The combination of a circuit controller of the switch type and aseparable actuator for said circuit controller, said circuit controllercomprising a housing, a movable electrical bridging member within saidhousing, means to hold said movable bridging member in closed circuitposition, means to move said bridging member into open circuit positionupon the occurrence of predetermined circuit conditions, and an aperturein said housing through which a detachable actuator may be inserted tomove the bridging member, said aperture being accessible only when saidcontroller is removed from the circuit.

2. The combination of a plurality of stationary spaced terminals of acircuit, and a circuit contrailer of the switch type, said circuitcontroller comprising a casing, a plurality of spaced external terminalsrigidly secured to the casing and being adapted to engage saidstationary terminals, movable circuit controlling mechanism within saidcasing, means for resetting said mechanism within said casing from opento closed circuit position, an aperture in the casing through which theresetting means may be actuated. said aperture being located betweensaid stationary spaced terminals and being accessible only when thedevice is removed from the stationary terminals.

3. A circuit breaker comprising a pivoted con tact member having aforked arm thereon, means to retain said pivoted contact member inclosed circuit position, an enclosing casing for said circuit breaker,and an aperture in the casing through which a removable contact memberactu ator may be inserted for engaging the forked member so as to rotatethe contact member about its pivot, but which aperture is onlyaccessible when the breaker is removed from the circuit.

4. The combination of a plurality of vertically aligned spring clips anda circuit breaker, said circuit breaker comprising a movable contact,means to hold said contact in a predetermined position, means to resetsaid movable contact, an enclosing casing, spaced, external terminalsrigidly fastened to said casing in substantially vertical alignment andbeing adapted to engage said spring clips, said movable contactpivctally mounted in a recess in said casing alignment with saidterminals, means for electricaliy conducting current iromsaid terminalsto said movable contact, said casing having an aperture therein throughwhich the movable contact may be reset, barriers on the casing forrestraining the position in which the casing may be inserted in thespring clips whereby the aperture is inaccessible when the casing isinserted in the spring clips, and means electrically operative foractuating the restraining means from closed circuit position to opencircuit position.

5. A circuit breaker comprising a casing, a fixed terminal and a movablecontact adapted to engage said terminal located within said casing,

a plurality of spaced external terminals rigidly secured to said casing,one of said terminals being connected to the movable contact and theother terminal being connected to the fixed terminal, means to move'said movable contact, means to restrain said movable contact in closedcircuit position, and said casing having an aperture through which themovable contact may be reset, saidaperture being located in said casingwhereby'the aperture is inaccessible when the breaker is connected inoperative position.

6. The combination of a removable circuit breaker and a casing having achamber therein, said casinghaving an external aperture which leads tothe said chamber, a fixed main terminal and a pivotally mounted movablebridging member within said chamber, a plurality of externally mountedterminals on said casing, one of said terminals being connected to themovable bridging member and the other of which is connected to the fixedterminal, means to hold the said movable bridging member in closedcircuit position, means to move said movable bridging member into opencircuit position upon the occurrence of predetermined circuitconditions, a

forked member on said movable bridging arm ad- Jacent to said aperturewhereby the movable contact arm may be reset, said aperture beinglocated in an inaccessible position when the breaker is connected in anelectric circuit, and means to indicate whether the bridging member isin open or closed circuit position.

7. In a circuit breaker, a housing enclosing said circuit breaker, amovable contact member and a. stationary contact member withinsaidhousing, a thermal element, a roller mounted upon the movablecontact member, a trigger pivotally mounted within the chamber of saidmovable contact member, said trigger including a latch whereby theroller will interiit with said latch when the contact member is inclosed circuit position, and said thermal strip being adapted to engagesaid pivotally mounted trigger to disengage said trigger from saidroller upon the occurrence of predetermined circuit conditions, therebyreleasing the contact member, and means on said movable contact memberto close the circuit, said means being accessible only when the circuitbreaker is removed from the circuit.

8. A circuit controller 0! the quick-break switch comprising a fixedterminal, a quickbreal: movable electrical bridging member adapted toengage said fixed contact terminal to complete the circuit, an enclosinginsulating casing for said fixed terminal and said bridging member, saidcasing having an opening therein, said bridging member pivotally mountedadjacent said opening, a detachable member for actuating said bridgingmember, means on said detachable member and said bridging member, saidmeans comprising an interiitting lug and recess, and said casing openingbeing accessible only when the breaker is removed from the circuit.

9. A circuit breaker of the quick-break type comprising a housing havinga small aperture therein, a plurality of fixed terminals, an oscillatoryelectrical bridging member adapted to be connected to or disconnectedfrom said fixed terminals, means adapted to rapidly move said bridgingmember from closed circuit to open circuit position, and an extensionwhereby said bridging member may be actuated from open to closed circuitposition on said bridging member located adjacent said small aperture,said extension being accessible only when said circuit breaker isremoved from the circuit.

WALTER, S. MAYER

